#!/bin/sh
#
# cluster-ssh.sh, Copyright © 2013 Matteo Cypriani <mcy@lm7.fr>
#
# This program is free software. It comes without any warranty, to
# the extent permitted by applicable law. You can redistribute it
# and/or modify it under the terms of the Do What The Fuck You Want
# To Public License, Version 2, as published by Sam Hocevar. See
# http://sam.zoy.org/wtfpl/COPYING for more details.
#
# Open an SSH interactive shell on a list of remote hosts, opening one
# GNU Screen tab per host.

print_usage()
{
  echo "Usage: $0 [-l login] <hosts_list>"
}

# We must have either 3 arguments...
if [ $# -eq 3 ] ; then
  # Parse the optional arguments
  if [ "$1" = "-l" ] ; then
    LOGIN="$2"
    shift
    shift
  else # Option unknown
    print_usage
    exit 1
  fi

# ... or only 1
elif [ $# -ne 1 ] ; then
  print_usage
  exit 3
fi

# Hosts' list file
if [ -z "$XDG_CONFIG_HOME" ] ; then
  XDG_CONFIG_HOME="$HOME/.config"
fi
HOSTS_FILE="$XDG_CONFIG_HOME/cluster/$1.lst"
shift
echo "Using file '$HOSTS_FILE' as hosts' list."
if [ ! -f "$HOSTS_FILE" ] ; then
  echo "The hosts' list file doesn't exist or is not a regular file."
  exit 2
fi

# Login
if [ -n "$LOGIN" ] ; then
  echo "Login: $LOGIN"
  LOGIN="${LOGIN}@"
fi

# Create the screen tabs
while read -r HOST ; do
  SSH="ssh ${LOGIN}${HOST}"
  # shellcheck disable=SC2086
  screen -t "$SSH" $SSH
done <"$HOSTS_FILE"